Unravelling the complex tectonics of western and northwestern Canada using broadband seismic data

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The objectives of my research program focus on outstanding questions relating to the evolution and dynamics of the solid Earth, in particular the crust and upper mantle associated with tectonically active regions. I approach these objectives through the application and development of detailed, 3D seismic velocity models of the onshore and offshore obtained using networks of broadband seismic instruments. The sophisticated processing and imaging tools, developed in house and with close collaborators, enable the extraction of maximum structural information from available seismic datasets, providing robust, statistically sound analysis and interpretation. Specifically, my research focuses on the actively deforming regions of western and northern Canada, as revealed through the lens of seismic velocity and associated physical properties, as well as the location and patterns of seismicity. Ultimately, these objectives will improve our assessment of earthquake and related hazards, and therefore mitigation procedures, as well as advancing deep mineral system knowledge across western and northern Canada. In western Canada, the North American continent is juxtaposed against a complex offshore tectonic system. This includes the Cascadia Subduction Zone in the south, where the Juan de Fuca and Gorda Plates are subducting beneath the margin. In the north, the transpressional Queen Charlotte Fault system extends from southern Haida Gwaii northwards to Alaska. In between these two plate boundary systems lies the Queen Charlotte Triple Junction, a complex area of small plates and plate fragments that accommodate this change in deformation style. This broad region on the BC coast is home to the highest seismic hazard in Canada and can slip in large (and sometimes giant) earthquakes. The Northern Canadian Cordillera (NCC) and southwest Canadian Arctic has been tectonically active for ~250 Myr and is host to numerous mineral and geothermal energy resources, as well as transportation and energy corridors vital to northern residents. This region is also home to significant seismicity, distributed broadly across the NCC and extending northwards off the Mackenzie Delta into the Beaufort Sea. As a result of continued climate warming, this northern region is particularly prone to mass wasting events and coastal erosion as a result of melting permafrost, making it more susceptible to ground shaking from local and regional earthquakes. In the proposed research, I plan to use all available seismic data within western and northern Canada to constrain these complex tectonic systems, including the Western Arctic Regional Network of Seismographs (WARNS), a network I deployed with colleagues. My long-term vision includes future off-shore deployments in several key areas, including the Beaufort Sea and Queen Charlotte Triple Junction, which will not only be highly complementary to this work, but capitalize on important opportunities for the Canadian geoscience community.